Wellcraft Excel 26SE Propeller Size

[jfrdcl@gmail.com]

Hello All,

I was wondering if someone knew some info regarding propeller size, WOT and cruising RPMs and speed for a 1996 Wellcraft Excel 26SE with a Volvo Penta 5.8FL setup. I previous had a 14.5x19p prop but I'm told it wasn't reaching the RPM spec for WOT (4200-4500?). Now I have a 17p prop. I believe it's a 15x17p. With the current prop, I achieved the below RPMs and speeds.

I understand the prop should allow achieving the rated WOT RPM, but these speeds seem pretty low. Conditions were 2 people with 1/2 tank of gas. With the 14.5x19p prop last year I recall cruising around 24kts @ 3200-3300 RPMs but I do not recall what I got for WOT. I'm also being told my tachometer is reading about 200 RPMs low, but that doesn't seem to make sense from the below data as that would imply a 3600RPM (seems high) for just a 20.5kts cruise.

GPS HEADING Notes RPMs "GPS SPEED(KTS)" "SPEED(MPH)"
215 M Against Tide 3000 12.6 14.5
219 M 3200 17.7 20.4
210 M 3400 20.5 23.6
219 M 3600 23.8 27.4
200 M WOT 4200 27.8 32.0
201 M WOT 4200 27.9 32.1
058 M With Tide 2800 12.5 14.4
059 M 3300 19.9 22.9
046 M 3400 22 25.3
063 M 3600 24 27.6

Any feedback is much appreciated!

Thanks,
John